Endangered Species Act turns 40

Guests

Peter Alagona:Associate professor of history, geography and environmental studies at the University of California, Santa Barbara, and author of "After the Grizzly: Endangered Species and the Politics of Place in California"

According to the U.S. Fish and Wildlife Service, 99 percent of all plants and animals ever protected under the Endangered Species Act have been saved from extinction. Critics, however, point out that only 1 percent of the protected species have recovered enough to be removed from the list.

Forty years after President Richard Nixon signed the ESA into law, where do we stand? Why does the act still engender such controversy, and how have our views on conservation changed since 1973?